Using Cardiac Biomarkers in Veterinary Practice

DILATED CARDIOMYOPATHY IN SLENDER-TAILED MEERKATS (SURICATA SURICATTA) UNDER HUMAN CARE

Meerkats (Suricata suricatta) housed at two accredited zoological institutions in the United States were evaluated via echocardiography, thoracic radiography, and blood biomarkers-taurine and feline N-terminal pro-B-type natriuretic peptide-to determine the prevalence and severity of dilated cardiomyopathy (DCM) in both populations. In total, 24 meerkats were evaluated and 7 were diagnosed with DCM based on the following parameters: left ventricular internal diameter at end diastole > 1.30 cm, left ventricular internal diameter at end systole > 1.10 cm, and a fractional shortening of <18%. Echocardiographic parameters were identified and reported for normal and affected meerkats, whereas thoracic radiographs were not useful for screening for DCM. Meerkats with DCM were treated with pimobendan and/or benazepril and furosemide if indicated. Seven meerkats died during the study period, with the majority exhibiting myocardial fibrosis. Of the blood parameters tested, elevated taurine levels were associated with DCM. Further research is necessary to characterize the etiology of DCM in meerkats.

The Pulse of It: Dietary Inclusion of Up to 45% Whole Pulse Ingredients with Chicken Meal and Pea Starch in a Complete and Balanced Diet Does Not Affect Cardiac Function, Fasted Sulfur Amino Acid Status, or Other Gross Measures of Health in Adult Dogs

BACKGROUND

Pulses are an attractive alternative protein source for all mammals; however, recent reports suggest that these ingredients may be related to developing dilated cardiomyopathy in dogs.

OBJECTIVES

The primary objective of this study was to quantify the effects of dietary pulse intake by adult dogs on cardiac function using echocardiographic measurements and cardiac biomarkers N-terminal pro-B-type natriuretic peptide and cardiac troponin I (cTnI). Second, to investigate the effects of pulse consumption on plasma sulfur amino acid (SAA) concentrations as pulses are generally low in SAA and may limit taurine synthesis. Last, to assess the general safety and efficacy of feeding pulse-containing diets on canine body composition and hematological and biochemical indices.

METHODS

Twenty-eight privately-owned domestic Siberian Huskies (13 females; 4 intact, and 15 males; 6 intact) with a mean age of 5.3 ± 2.8 y (± SD) were randomly assigned to 1 of 4 dietary treatments (n = 7/treatment), with equal micronutrient supplementation and increasing whole pulse ingredient inclusion (0%, 15%, 30%, and 45%) with pea starch used to balance protein and energy.

RESULTS

After 20 wks of feeding, there were no differences (P > 0.05) in echocardiographic parameters, N-terminal pro-B-type natriuretic peptide, and cTnI concentrations among treatments or across time within treatment (P > 0.05), indicating no differences in cardiac function among treatments. Concentrations of cTnI remained below the safe upper limit of 0.2 ng/mL for all dogs. Plasma SAA status, body composition, and hematological and biochemical indices were similar among treatments and over time (P > 0.05).

CONCLUSIONS

The results from this study suggest that increasing the inclusion of pulses up to 45% with the removal of grains and equal micronutrient supplementation does not impact cardiac function concurrent with dilated cardiomyopathy, body composition, or SAA status and is safe for healthy adult dogs to consume when fed for 20 wks.

N-terminal brain natriuretic peptide, cardiac troponin-I, and point-of-care ultrasound in dogs with cardiac and noncardiac causes of nonhemorrhagic ascites

BACKGROUND

Nonhemorrhagic ascites (NHA) can be caused by cardiac diseases (cNHA) and noncardiac diseases (ncNHA). N-terminal brain natriuretic peptide (NT-proBNP), cardiac troponin-I (cTnI), and point-of-care ultrasound (POCUS) may differentiate between cNHA and ncNHA.

HYPOTHESIS/OBJECTIVES

We compared NT-proBNP and cTnI concentrations as well as POCUS findings in dogs presented with cNHA and ncNHA.

ANIMALS

Dogs (n = 60) were enrolled based on identification of NHA with an effusion packed cell volume < 10%.

METHODS

Blood samples were collected and POCUS was performed on all dogs. Dogs were diagnosed with cNHA (n = 28) or ncNHA (n = 32) based on echocardiography. The cNHA group was subdivided into cardiac non-pericardial disease (n = 17) and pericardial disease (n = 11).

RESULTS

The NT-proBNP concentration (median; range pmol/L) was significantly higher in the cNHA group (4510; 250-10 000) compared to the ncNHA group (739.5; 250-10 000; P = .01), with a sensitivity of 53.8% and specificity of 85.7% using a cut-off of 4092 pmol/L. The NT-proBNP concentrations were significantly higher in the cardiac non-pericardial disease group (8339; 282-10 000) compared with the pericardial disease group (692.5; 250-4928; P = .002). A significant difference in cTnI concentration (median; range ng/L) between the cNHA group (300; 23-112 612) and ncNHA group (181; 17-37 549) was not detected (P = .41). A significantly higher number of dogs had hepatic venous and caudal vena cava distension in the cNHA group compared to the ncNHA group, respectively (18/28 vs 3/29, P < .0001 and 13/27 vs 2/29, P < .001). Gall bladder wall edema was not significantly different between groups (4/28 vs 3/29, P = .74).

CONCLUSIONS AND CLINICAL IMPORTANCE

NT-proBNP concentration and POCUS help distinguish between cNHA and ncNHA.

Can cartilage intermediate layer protein 1 (CILP1) use as a novel biomarker for canine myxomatous mitral valve degeneration levels or not?

BACKGROUND

Myxomatous mitral valve degeneration (MMVD) is the most common degenerative heart disease in dogs and is associated with irreversible changes in the valve tissue. Although traditional cardiac biomarkers are efficient for diagnosing MMVD, there are limitations, therefore, it is important to find novel biomarkers. Cartilage intermediate layer protein 1 (CILP1), an extracellular matrix-derived protein, acts as a transforming growth factor-β antagonist and is involved in myocardial fibrosis. This study aimed to evaluate serum CILP1 levels in canines with MMVD. Dogs with MMVD were staged according to the American College of Veterinary Internal Medicine consensus guidelines. Data analysis was performed using the Mann-Whitney U test, Spearman's correlation, and receiver operating characteristic (ROC) curves.

RESULTS

CILP1 levels were elevated in dogs with MMVD (n = 27) compared to healthy controls (n = 8). Furthermore, results showed that CILP1 levels were significantly higher in stage C group dogs compared to healthy controls. The ROC curve of CILP1 and NT-proBNP were good predictors of MMVD, although no similarity was observed between the two. Left ventricular end-diastolic diameter normalized to the body weight (LVIDdn) and left atrial to aorta dimension (LA/Ao) showed a strong association with CILP1 levels; however, no correlation was observed between CILP1 levels and vertebral heart size (VHS) and vertebral left atrial score (VLAS). The optimal cut-off value was selected from the ROC curve and dogs were classified according to the cut-off value (1.068 ng/mL, sensitivity 51.9%, specificity 100%). Results showed a significant association of CILP1 with cardiac remodeling indicators, such as VHS, VLAS, LA/Ao, and LVIDdn.

CONCLUSIONS

CILP1 can be an indicator of cardiac remodeling in canines with MMVD and therefore, can be used as an MMVD biomarker.

EVALUATION OF PLASMA CARDIAC TROPONIN I IN ASIAN ELEPHANTS (ELEPHAS MAXIMUS) USING TWO CLINICAL ANALYZERS

Cardiac troponin I (cTnI) is specific to myocardial tissue, highly conserved across taxa, and a reliable indicator of myocardial disease in human and veterinary medicine. Biomarkers, like cTnI, may be useful for cardiac evaluation of elephants because the application of other modalities is complicated by the size of the animal. The goal of this study was to establish observed ranges for plasma cTnI in Asian elephants (Elephas maximus) measured by two point-of-care analyzers. Blood was collected from captive juvenile (≤15 yr; n = 9), adult (16-50 yr; n = 42), and geriatric (>50 yr; n = 16) elephants. Following centrifugation, heparinized plasma was stored at 5°C prior to and in between analyses on iSTAT (Abbott Point of Care Inc, Princeton, NJ 08540, USA) and HUBI-QUANpro (Humiasis Co, Ltd, Anyang-si 14042, South Korea) analyzers. With the exception of two results, plasma concentrations of cTnI were below the limit of quantification (LOQ < 0.05 ng/ml) for the HUBI-QUANpro (n = 64), which prohibited comparison between the two analyzers. Observed ranges were determined for plasma cTnI concentrations reported by the iSTAT for the entire population sampled (n = 58; mean 0.011 ng/ml; SD ± 0.013 ng/ml; range 0.00-0.07 ng/ml; 95% CI 0.008-0.015 ng/ml; median 0.01 ng/ml) and with outliers excluded (n = 50; mean 0.007 ng/ml; SD ± 0.007 ng/ml; range 0.00-0.02 ng/ml; 95% CI 0.005-0.009 ng/ml; median 0.01 ng/ml). No significant differences were observed between age classes (P = 0.70) or sexes (P = 0.34). Higher cTnI concentrations were significantly correlated with increasing age (Pearson's r = 0.426; P = 0.002). Future studies are warranted to investigate the diagnostic potential of plasma cTnI in Asian elephants.

Evaluation of blood pressure and NT-proBNP in pugs with and without clinical signs of Brachycephalic Obstructive Airway Syndrome

Brachycephalic Obstructive Airway Syndrome (BOAS) is a pathologic condition of the upper airways, frequently occurring in dogs of brachycephalic breeds including pugs. It has been suspected that BOAS may be associated with cardiovascular changes and an increased risk for hypertension. The cardiac biomarker NT-proBNP can help to differentiate cardiac from non-cardiac respiratory distress. A possible influence of BOAS on NT-proBNP values has not been investigated, however. The aim of the current study was to examine blood pressure and NT-proBNP levels in pugs with and without clinical signs of BOAS and compare them to values of mesocephalic dogs. For this purpose, NT-proBNP values of 42 pugs and six mesocephalic dogs and blood pressure measurements of 34 pugs and four mesocephalic dogs were explored in the present study. Pugs were examined for clinical signs of BOAS at rest and after a submaximal fitness test, and a functional BOAS grading was applied. Blood pressure (BP) was measured at the beginning and end of the study day and NT-proBNP values were obtained before and after exercise. Measured values of pugs with different degrees of clinical impairment due to BOAS were compared among each other as well as to the CG. In terms of systolic, mean, diastolic BP, and NT-pro BNP, there were no relevant differences between pugs and the CG and no obvious connection between the severity of BOAS symptoms and measured values. BP values of all groups were lower at the second measurement at the end of the study day. NT-proBNP measurements were higher after exercise. BP and NT-proBNP values in all groups were in agreement with commonly used reference ranges. In conclusion, the study adds evidence, that BP and NT-proBNP values did not differ between mesocephalic dogs and pugs with different levels of severity of BOAS but between the measurement times. Thus, in the present study, excitement and exercise seemed to have a greater influence on BP and NT-proBNP values than presence of BOAS symptoms or breed. Discovered values show that the commonly used reference ranges for BP and NT-proBNP are applicable in pugs. This indicates that NT-proBNP can be used to differentiate between cardiac and non-cardiac respiratory distress even in pugs with clinical symptoms of BOAS.

Clinical findings associated with N-terminal pro-B-type natriuretic peptide measurement in dogs and cats attending first opinion veterinary practices

BACKGROUND

Clinical findings associated with N-terminal pro-B-type natriuretic peptide (NT-proBNP) measurement in dogs and cats in primary practice, and their relevance to published measurement indications, have not been described.

METHODS

Using electronic health record data collected by the Small Animal Veterinary Surveillance Network, appointments in which NT-proBNP was measured were identified using keyword-based text filtering. For these appointments, clinical findings were manually identified from each patient's clinical narrative (CN) and their frequencies described.

RESULTS

CNs of 3510 appointments (357 dogs and 257 cats) from 99practices were evaluated. The most frequently recorded clinical findings in dogs were: heart murmur (n = 147, 41.2% (95% confidence interval (CI) = 36.1%-46.3%), coughing (n = 83, 23.2% (95% CI = 18.8%-27.6%)) and panting (n = 58, 16.2% (95% CI = 12.4%-20.0%)) and in cats: heart murmur (n = 143, 55.6% (95% CI = 49.5%-61.7%)), suspected thromboembolism (n = 88, 34.2% (95% CI = 28.4%-40.0%)) and weight loss (n = 53, 20.6% (95% CI = 15.7%-25.5%)). Dyspnoea and tachypnoea were infrequently reported in dogs (n = 29, 8.1% (95% CI = 5.3%-10.9%) and n = 21, 5.9% (95% CI = 3.5%-8.3%), respectively) and cats (n = 26, 10.1% (95% CI = 6.4%-13.8%) and n = 36, 14.0% (95% CI = 9.8%-18.2%), respectively).

CONCLUSION

Clinical findings referable to cardiac disease were recorded contemporaneously with NT-proBNP measurement and suggested both published and other indications (coughing (in dogs and cats), and serial measurements and thromboembolism (in cats)) for testing.

Potential applications of aptamers in veterinary science

Aptamers are small nucleic acids that fold in a three-dimensional conformation allowing them to bind specifically to a target. This target can be an organic molecule, free or carried in cells or tissues, or inorganic components, such as metal ions. Analogous to monoclonal antibodies, aptamers however have certain advantages over the latter: e.g., high specificity for their target, no to low immunogenicity and easy in vitro selection. Since their discovery more than 30 years ago, aptamers have led to various applications, although mainly restricted to basic research. This work reviews the applications of aptamers in veterinary science to date. First, we present aptamers, how they are selected and their properties, then we give examples of applications in food and environmental safety, as well as in diagnosis and medical treatment in the field of veterinary medicine. Because examples of applications in veterinary medicine are scarce, we explore the potential avenues for future applications based on discoveries made in human medicine. Aptamers may offer new possibilities for veterinarians to diagnose certain diseases—particularly infectious diseases—more rapidly or “at the patient’s bedside”. All the examples highlight the growing interest in aptamers and the premises of a potential market. Aptamers may benefit animals as well as their owners, breeders and even public health in a “One Health” approach.

Updates on Laboratory Evaluation of Feline Cardiac Diseases

Laboratory tests can be altered in cardiovascular diseases and the investigation of specific tests or biomarkers may provide additional information about myocardial damage. Traditional laboratory tests, such as cell blood count, serum biochemistry, and coagulation, can be useful in investigating patients, but are not specific. However, markers like Troponin and Natriuretic Peptides may possibly furnish further data on myocardium damage and can be used in both studying and monitoring cats with cardiac disease. Moreover, the evaluation of the thyroid profile is very important as hyperthyroid cats concomitant cardiovascular diseases are very common and they can also be a direct consequence of endocrinopathy. The purpose of this manuscript is to provide the widest possible overview of what is present in the literature about the feline clinical pathology of heart diseases through a rational division of the main alterations of traditional tests and biomarkers.

THORACIC RADIOGRAPHY AND TRANSTHORACIC ECHOCARDIOGRAPHY IN CLINICALLY HEALTHY RING-TAILED LEMURS (LEMUR CATTA)

Cardiac disease has been recognized as a major cause of death in captive nonhuman primates, which necessitates diagnostic (imaging) techniques to screen for and diagnose preclinical and clinical stages of possible cardiac conditions. Echocardiography is currently the most commonly used diagnostic tool for evaluation of cardiac anatomy and function. Complete with thoracic radiography and blood levels of two cardiac biomarkers, N-terminal probrain natriuretic peptide (NT-proBNP) and cardiac troponin T (cTnT), it gives an extensive examination of the cardiorespiratory system. The purpose of this cross-sectional cohort study is to describe normal thoracic anatomy using thoracic radiography, and to provide normal values for echocardiographic measurements in 20 ring-tailed lemurs (Lemur catta). Additionally, cardiac biomarkers were determined. Three radiographic projections of the thoracic cavity and a complete transthoracic echocardiography were performed in 20 clinically healthy ring-tailed lemurs during their annual health examinations. Similar standard right parasternal and left apical echocardiographic images were obtained as described in dogs and cats and normal values for routine two-dimensional (2D-), time-motion (M-) and Doppler mode measurements were generated. Furthermore, a noninvasive smartphone base ECG recording and blood concentrations of cardiac biomarkers were obtained. Other radiographic measurements are provided for the skeletal and respiratory systems such as the trachea to inlet ratio and tracheal inclination. Knowledge of the normal radiographic thoracic and echocardiographic anatomy and function are fundamental for the diagnosis and follow-up of cardiac disease in affected individuals and for species screening, and will be of added value in future research in and conservation of this endangered species.

Canine Traditional Laboratory Tests and Cardiac Biomarkers

In small animals, cardiac disease evaluation through laboratory tests can be a challenge. This review will present both historical and updated perspectives on the clinical pathology of cardiac diseases in dogs and demonstrate that laboratory tests are useful tools for the management of patients with cardiac diseases.

Heart-fatty acid binding protein in dogs with degenerative valvular disease and dilated cardiomyopathy

The study objective was to investigate heart-fatty acid binding protein (HFABP) concentrations in dogs with degenerative valvular disease (MVD) and dilated cardiomyopathy (DCM), and its potential as a prognostic factor. Plasma HFABP, N-terminal pro brain natriuretic peptide (NTproBNP) and serum cardiac troponin I (cTnI) levels were measured in 21 control dogs, 23 dogs with MVD and 13 dogs with DCM, with repeated sampling at 1 and 3 months after initial presentation. All dogs were followed up after 6 and 12 months to verify survival. Heart-fatty acid binding protein concentrations were significantly higher in dogs with MVD and DCM than controls at initial presentation, and after 1 month in dogs with MVD. For dogs with DCM, a significant reduction in HFABP levels over time was observed. Comparing ACVIM stages, highest HFABP concentrations were detected in ACVIM stage C dogs compared to stage B, with the lowest levels seen in controls, and a reduction over time in stage C dogs was present. Similarly, cTnI concentrations were higher in DCM and stage C in comparison to control dogs and reduced over time, while NTproBNP concentrations were only higher in diseased dogs at 1 month. Heart-fatty acid binding protein and cTnI levels at initial presentation and ACVIM disease stage were independent predictors of survival in a univariate analysis. The elevation of HFABP in dogs with MVD and DCM in comparison to controls, its association with disease severity, and its potential in predicting reduced survival, suggest that HFABP might be useful as marker for canine MVD and DCM.

Artificial cardiac pacemaker placement in dogs with a cohort of myocarditis suspects and association of ultrasensitive cardiac troponin I with survival

INTRODUCTION

Artificial cardiac pacemakers (APs) are a common treatment for symptomatic bradyarrhythmias in dogs, some of which may be triggered by underlying myocarditis. Severely elevated cardiac troponin I (cTnI) concentrations support a diagnosis of myocarditis. The association of ultrasensitive-cTnI (US-cTnI) concentration with survival in a large cohort of dogs receiving APs is not described.

ANIMALS, MATERIALS, AND METHODS

The study included 110 dogs receiving APs over a 5-year period. Medical records were retrospectively reviewed to characterize the entire population receiving APs, with further analysis in dogs with preprocedural US-cTnI concentrations (n = 64) classified as normal/group 1 (n = 11), mildly to moderately elevated/group 2 (n = 27), and severely elevated/myocarditis suspects/group 3 (n = 26).

RESULTS

Median survival time was 1079 days for the entire population, 1167 days for group 2, 949 days for group 3, and not met in group 1. There was not a statistically significant difference in survival between group 2 and group 3. Overall, US-cTnI had a mild, negative association with survival. Age had a stronger negative association. Infectious etiologies were identified in a minority of group 3 cases. A possible association between severely elevated US-cTnI and a sudden death outcome was noted.

CONCLUSIONS

The negative association of US-cTnI with survival outcomes was mild, with age having a larger effect. Although a sudden death outcome may be seen more commonly in myocarditis suspects, group 3 survival time was similar to that of the entire canine population. Plausible infectious causes of myocarditis were infrequently identified.

Bacterial endocarditis and increased cardiac troponin I levels in a brown howler monkey (Alouatta guariba clamitans) with an interventricular septal defect

A brown howler monkey (Alouatta guariba clamitans) was presented with lethargy, hyporexia, cough and heart murmur. The complementary tests and necropsy revealed pleuropneumonia, bacterial endocarditis and interventricular septal defect. To the best of our knowledge, this is the first report of increased cardiac troponin I levels in this species.

Successful management of minoxidil toxicosis in a dog

CASE DESCRIPTION A 2-year-old sexually intact female mixed-breed dog was evaluated at an emergency hospital approximately 5 hours after ingestion of an unknown amount of over-the-counter topical hair growth promoter containing 5% minoxidil foam. Vomiting and signs of lethargy were reported by the owner, and physical examination revealed tachycardia and hypotension. No treatments were performed, and the dog was transferred to a veterinary referral hospital for management of suspected minoxidil toxicosis. CLINICAL FINDINGS On arrival at the referral hospital, the dog was tachycardic (heart rate, 200 to 220 beats/min) and hypotensive (systolic arterial blood pressure, 70 mm Hg). Electrocardiography revealed a regular, narrow-complex tachycardia with no evidence of ventricular ectopy. TREATMENT AND OUTCOME Hypotension was effectively managed with a constant rate infusion of dopamine hydrochloride (12.5 μg/kg/min [5.7 μg/lb/min], IV). Once normotensive, the dog remained tachycardic and a constant rate infusion of esmolol hydrochloride (40 μg/kg/min [18.2 μg/lb/min], IV) was initiated for heart rate control. A lipid emulsion was administered IV as a potential antidote for the toxic effects of the lipophilic minoxidil, with an initial bolus of 1.5 mL/kg (0.7 mL/lb) given over 15 minutes followed by a continuous rate infusion at 0.25 mL/kg/min (0.11 mL/lb/min) for 60 minutes. While hospitalized, the dog also received maropitant citrate and ondansetron. Resolution of clinical signs was achieved with treatment, and the dog was discharged from the hospital 36 hours after admission. Four days later, the owner reported that the dog had made a full recovery and had returned to its typical behavior and activity level at home. CLINICAL RELEVANCE To the authors' knowledge, this is the first report of successful clinical management of accidental minoxidil toxicosis in a dog.

Evaluation of cardiopulmonary and inflammatory markers in dogs with heartworm infection during treatment with the 2014 American Heartworm Society recommended treatment protocol

Background

Heartworm disease in dogs is a life-threatening parasitic disease. Although adulticide treatment with melarsomine has been proven to be the most effective, complications associated with adulticide treatment are major concerns for clinicians.

Methods

This study evaluated the change in levels of D-dimer, interleukin-6, C-reactive protein and cardiac troponin I in 12 dogs with different severities of heartworm infection treated by the American Heartworm Society (AHS) recommended protocol during the treatment period. The serum levels of several markers were measured on the day of diagnosis (T-60), before the initiation of melarsomine therapy (T0), 1 day after the first injection (T1), 1 week after the first injection (T7), 1 month after the first injection (T30), 1 day after the second injection (T31), 1 day after the third injection (T32), 1 week after the third injection (T39), 1 month after the third injection (T62), 2 months after the third injection (T92), 3 months after the third injection (T122), and 6 months after the third injection (T182).

Results

The serum levels of these markers were significantly different at the test time point after melarsomine treatment and also differed significantly according to the stage of heartworm disease in the dogs.

Conclusion

This study found that monitoring of inflammatory and hemostatic markers in dogs with heartworm disease being treated with melarsomine might be beneficial in predicting the clinical outcomes and complications associated with melarsomine treatment.

N-terminal-pro brain natriuretic peptides in dogs and cats: A technical and clinical review

Biomarkers are quantitative indicators of biological processes performed by an organ or system. In recent years, natriuretic peptides (NPs) have emerged as important tools in the diagnosis and therapeutic monitoring of heart diseases. Research has shown that serum and plasma levels of N-terminal pro brain NP (NT-proBNP) in dogs and cats are the only biomarkers that afford to diagnose and monitor congestive processes and, indirectly, the myocardial function of small animals. The present review discusses the peer-reviewed specialized literature about NT-proBNP and presents and compares the potential clinical applications of this NP in veterinary medicine of small animals, considering diagnosis, follow-up, and prognosis of myocardial or systemic diseases. The relevance of NT-proBNP is associated with sample stability, easy determination in laboratory, sensitivity, accuracy, and the possibility to analyze myocardial function. These advantages are specially important when NT-proBNP is compared with other cardiac biomarkers, mostly those that indicate the integrity of the myocardial cell. Fast NT-proBNP assays are marketed today and may be used in association with complementary tests. Together, these methods are an important source of information in differential diagnosis of heart and lung diseases as well in the early diagnosis of cardiopathy in dogs and cats, proving valuable tools in treatment and prognosis.

Cardiac Troponin I and Amino-Terminal Pro B-Type Natriuretic Peptide in Dogs With Stable Chronic Kidney Disease

Background

Increased concentrations of N‐terminal pro B‐type natriuretic peptide (NT‐proBNP) and cardiac troponin I (cTnI) in dogs with azotemia have been documented. Knowledge of mechanisms behind increased concentrations of cardiac biomarkers in dogs with azotemia is warranted for correct interpretation of test results.

Objectives

The aim of the article was to investigate possible associations between plasma concentrations of cTnI and NT‐proBNP, respectively, and patient characteristics, glomerular filtration rate (GFR), a plasma volume factor (PVF) derived from scintigraphic examination (PVf), systolic blood pressure (SBP), selected hematologic and biochemical variables, and echocardiographic measurements in dogs with stable chronic kidney disease (CKD) and in healthy dogs.

Animals

Fifty student‐, staff‐, and client‐owned dogs were included. Twenty‐three of the dogs were healthy and 27 were diagnosed with CKD.

Methods

In this cross‐sectional observational study, dogs with a previous diagnosis of CKD and healthy control dogs were included. At inclusion, all dogs were characterized by physical examination, repeated blood pressure measurements, complete urinalysis, hematology and biochemistry panel, echocardiography, abdominal ultrasound examination of the entire urinary tract, and scintigraphic examination for measurement of GFR.

Results

Plasma volume factor and PCV were independently associated with NT‐proBNP (Radj2 = 0.42; P < .0001). Age, body weight (BW), and SBP were independently associated with cTnI (Radj2 = 0.50; P < .0001).

Conclusions and Clinical Importance

Neither NT‐proBNP nor cTnI concentrations were independently associated with measured GFR. Thus, findings were not suggestive of passive accumulation of either marker, suggesting that increased circulating concentrations of cTnI and NT‐proBNP can be interpreted similarly in dogs with stable CKD as in dogs without CKD.

Association between Survival Time and Changes in NT-proBNP in Cats Treated for Congestive Heart Failure

Background

Reductions in N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP) concentrations after treatment have been associated with improved survival in people with congestive heart failure (CHF), but have not been reported in cats with CHF.

Objectives

To evaluate changes in NT‐proBNP concentrations in cats with CHF after treatment and determine whether serial NT‐proBNP measurements provide prognostic information.

Animals

Thirty‐one client‐owned cats.

Methods

Prospective, observational study in cats with new onset CHF secondary to cardiomyopathy. Concentrations of NT‐proBNP were measured within 4 hours of admission to the hospital, on the day of discharge, and at re‐evaluation 7–10 days later.

Results

Median NT‐proBNP concentrations decreased significantly from admission (1,713 pmol/L [range, 160–3,784 pmol/L]) to discharge (902 pmol/L [range, 147–3,223 pmol/L]); P = .005) and from admission to re‐evaluation (1,124 pmol/L [range, 111–2,727 pmol/L]; P = .024). Median survival time was 109 days (range, 1–709 days), with 5 cats still alive at the time of analysis. Cats with a larger percent decrease in NT‐proBNP from admission to discharge had a longer survival time (P = .048). Cats with evidence of active CHF at the time of re‐evaluation (P = .010) and cats whose owners had difficulty administering medications (P = .045) had shorter survival times.

Conclusions and clinical importance

Cats with a larger percent decrease in NT‐proBNP during hospitalization and no evidence of CHF at the time of re‐evaluation had longer survival times. Additional studies are needed to determine whether NT‐proBNP can help guide treatment in cats with CHF.

Biomarkers in Veterinary Medicine

This article summarizes the relevant definitions related to biomarkers; reviews the general processes related to biomarker discovery and ultimate acceptance and use; and finally summarizes and reviews, to the extent possible, examples of the types of biomarkers used in animal species within veterinary clinical practice and human and veterinary drug development. We highlight opportunities for collaboration and coordination of research within the veterinary community and leveraging of resources from human medicine to support biomarker discovery and validation efforts for veterinary medicine.